Glass sheet failures compromise safety

Contractors yesterday removed glass sheets from a veranda
outside the University of Otago's Information Services
Building as a safety precaution after a sheet of glass
spontaneously shattered on to the footpath in the week
before Christmas. Photo by Craig Baxter.

The University of Otago is auditing the safety of
architectural glass sheets in some of its more than 200
buildings as it faces problems with spontaneously shattering
glass, including an incident in the week before Christmas.

The audit comes as a sheet of glass over a veranda outside
the university's Information Services Building shattered on
to the Cumberland St footpath.

University director of property services Barry MacKay said
''fortunately'' no pedestrians were hurt as a result.''

The cause is yet to be determined and the university is
investigating how the glass broke. However, the rest of the
glass over this veranda is being removed as a precaution and
checked.''

Earlier this month Mr MacKay, responding to an Otago Daily
Times official information request, said an audit of
internal glazing had been launched to check safety across
some of the institution's more than 200 buildings.

This could lead to the institution taking steps to better
protect those inside up to a dozen of its own buildings.

The audit follows a glass ceiling panel shattering inside the
Dunedin City Council-owned Wall Street mall in April,
showering two men - one in a wheelchair - with glass
fragments.

The pair escaped injury, but the incident prompted a warning
any repeat had the potential to be fatal and led to the
council spending $60,000 to retrofit a protective film under
each glass panel inside the mall.

Mr MacKay said the university's checks would pay particular
attention to horizontal and canopy panels, following problems
with shattering glass ''over the past few years'', he said.''

This problem potentially affects around a dozen of the
university's more than 200 buildings and the cost of
resolving it is unknown at this stage,'' Mr MacKay said.

The university also released emails between staff revealing
an incident similar to that inside the Wall Street mall had
also occurred at Arana College on March 26.

An email from the college's property manager, Brian O'Kane,
to a university staff member said two large sheets of glass -
forming part of canopy outside the main dining hall - had
''spontaneously shattered and fell to the ground''.

There were no injuries, ''but there would have been if
residents [or] staff were underneath'', he wrote.

University property services strategy and planning manager
Sue Larkins, who received the email, wrote back: ''Yuck!
Thank goodness no-one was injured!''

She later said about the use of toughened glass, ''a
fundamental rethink may be in order''.

The incident inside the Wall Street mall occurred weeks
later, and was eventually blamed on nickel sulphide inclusion
in the glass.

The nickel inclusions sometimes inadvertently occurred during
the manufacture of float glass that was later toughened, and
could on average affect one in 25,000 sheets of glass.

Parker Warburton Team Architects Ltd director Simon Parker -
whose firm was the lead architect behind the Wall Street mall
- said glazing codes were tightened in 2010, and other
Dunedin buildings would need to be retrofitted if owners
wanted to meet requirements.

Mr MacKay said the university used ''a large amount of
glass'' inside its buildings, particularly for balustrades.

On the ''odd occasions'' panels had shattered in the past,
the incidents had been managed by replacement, improvements
to fixing systems and using protective films, Mr MacKay said.

However, the most recent change in glazing standards had
prompted the university's audit, he said.

''Once the audit is complete we will make a risk-based
assessment of the options for protecting the building
occupants and users, including the use of protective film.

If it is decided to use protective film, a programme and cost
will need to be established.''